Section 3. Flowers Usually Perfect; Ovary Superior or Partly Inferior,

1—4-celled; leaves simple, persistent in the North American species.

XIII. Olacaceæ (p. 336). Calyx and corolla 4—6-lobed; ovary 1—4-celled; fruit a drupe more or less inclosed in the enlarged disk of the flower; leaves alternate or fascicled, without stipules. XIV. Polygonaceæ (p. 338). Calyx 5-lobed; ovary 1-celled; fruit a nutlet inclosed in the thickened calyx; leaves alternate, their stipules sheathing the stems. XV. Nyctaginaceæ (p. 340). Calyx 5-lobed; ovary 1-celled; fruit a nutlet inclosed in the thickened calyx; leaves alternate or opposite, without stipules.

Subdivision 2. Petalatæ. Flowers with both calyx and corolla (without a corolla in Lauraceæ, in Liquidambar in Hamamelidaceæ, in Cercocarpus in Rosaceæ, in Euphorbiaceæ, in some species of Acer, in Reynosia, Condalia, and Krugiodendron in Rhamnaceæ, in Fremontia in Sterculiaceæ, in Chytraculia in Myrtaceæ, in Conocarpus in Combretaceæ and in some species of Fraxinus in Oleaceæ).